More than 850 permanent spinal related injuries result from diving accidents every year, according to the American Spinal Injury Association. One-third of these occur in swimming pools. Common injuries associated with diving accidents include spinal injuries and brain damage sometimes resulting in death. According to Dr. David Grossman, director of the Harborview Injury Prevention Research Center, “[T]he typical scenario leading to spinal injury involves simple misjudgment. There could be any number of reasons for the misjudgment—a person is intoxicated, the pool isn't marked or markings are ignored, they're too young, etc. But what happens when a diver hits the bottom of the pool is there will most likely be an impact to the head, right on the skull, that leads to a compression fracture of the spine, which is where the bone is—basically like a car hitting a wall. It just crushes onto itself and usually leads to a spinal-cord injury”. Additionally, the damage that occurs to spinal axons within the first few hours after injury is complex and it occurs in stages. The normal blood flow is disrupted, which causes oxygen deprivation to some of the tissues of the spinal cord. Bleeding into the injured area leads to swelling, which can further compress and damage spinal cord axons, the long, thin strings of nerve cell cytoplasm that carry electrical signals up and down the spinal cord. Over time, these and other events can contribute to more tissue degeneration and a greater loss of function.
Many of the injuries are not the fault of misjudgment but of bad swimming pool design. The current industry standards for depth, length and width of swimming pools are still too shallow of a depth for diving. Likewise, the transition slope, from the deep end to the shallow end of the pool is too sharp, resulting in the deep and shallow ends being too close to one another.
For swimming pools with diving boards, the Red Cross prefers a depth under the board of 11.5 feet, and 16.5 feet from the tip of the board to the transition slope. The YMCA has similar guidelines. Both groups advise homeowners not to allow diving, or to remove the boards, if their pool is less than this depth. The current National Spa and Pool Institute (NSPI) minimum depth is 7.5 feet, with 7 feet from the tip of the board to the transition slope. NSPI contest that this standard is safe if “properly used”. By proper use, the diver must “steer up” upon broaching the water to avoid the transition slope. When divers don't steer up, and when the transition slope is too sharp (less than the greater standard of 16.5 feet) they hit the bottom and injure themselves.
To further expose this problem, in the early '90s, John Wingfield, who coaches U.S. Olympic hopefuls, did a study for the U.S. Consumer Product Safety Commission, videotaping exactly what happens when people dive. When a pool's dimensions are within NSPI, divers, even while “steering up” could hit the transition slope at a speed high enough to cause catastrophic head and spinal injuries.
Not only do transition slopes present a danger, but also insufficient water depth. Although there might be “no diving” signs posted, in a study of diver awareness, the majority of divers failed to notice the sign or disregarded the sign. Statistical analyses show that the vast majority of accidents occur in water depths of about 3½ feet or less. People diving from the side of the pool enter the water at approximately 15 feet/sec. At this rate of speed, estimates of the point where downward motion ceases is around 12 feet, which is 8 feet deeper than the average depth at the shallow end of most pools. Divers who do not “steer up” will impact a four feet deep bottom at 10 feet/sec or greater.
John Wingfield believes that cost is probably the main reason that pools have not been redesigned. This invention allows an additional safety measure to be installed, providing a more cost efficient means to increased safety.
U.S. Pat. No. 3,997,924 issued to Jewitt is directed towards a swimming pool with an auxiliary fracturable floor for breaking a fall of a diver in an unduly rapid descent. In Jewitt, the bottom of the pool is equipped with chambers that may fracture to absorb energy when a diver dives into the bottom of the pool.
Currently, there are no swimming pool safety products that provide diver safety through a shock absorbing safety floor or modular tile. This invention provides a cost efficient means to increase the safety factor of swimming pools.